Field-magnet coil and method of manufacturing same



(No Model.)

J. JOHNSON & O. D. HASKINS. FIELD MAGNET 0011: AND METHOD OF MANUFAGTURING SAME.

*No 508,620. Patented Nov. 14, 1893.

NITED STATESv PATENT Fries.

JOSEPH JOHNSON AND OARYL D. HASKINS, OF LYNN, MASSACHUSETTS, AS- SIGNORS TO THE GENERAL ELECTRIC COMPANY, OF NEWV YORK.

FIELD-MAGNET COIL AND METHOD OF MANUFACTURING SAME.

SPECIFICATION forming part of Letters Patent No. 508,620, dated November 14, 1893- Application filed May 2, 1893. Serial No. 472,814. (No model.)

To all whom, it may concern:

Be it known that we, JOSEPH JOHNSON and CARYL D. HASKINS, citizens of the United States, and residents of Lynn, in the county of Essex and State of Massachusetts, have made certainnew and useful Improvementsin Field- Magnet Coils and Methods of Manufacturing the Same, of which the following is a specification.

Our invention relates to field coils and to methods for their manufacture, and has for its object to provide a simple form of such coil easily constructed and of small cost. To this end we construct such coils of a single piece of copper cast or stamped into suitable form and then provided with saw cuts into which insulation may be inserted, as illustrated and described more fully hereinafter.

In the accompanying drawings hereby referred to and made part of this specification, like letters refer to like parts throughout; and therein Figure 1 is a front elevation of a field-magnet coil of one turn made according to our invention. Fig. 2 is a side elevation of the parts shown in Fig. 1, and Figs. 3 and 4 are similar views of a modified form used where two coils or more are desired.

Referring by letter, A is the body of the coil, which is substantially a ring or tube of any desired cross-section; B is an extension or tongue forming a terminal at G and provided with holes D, D, into which the wires of the circuit may be inserted and secured by the set-screws S, S. A is a similar portion of the coil made in reverse shape from the part A and having a similar tongue or projection B, similar terminals 0, and holes D D for securing the circuit wires. It will be observed that the parts thus described are made right and left handed and that only two castings are necessary in the form shown, which are secured together at E by the countersunk screws T T, Fig. 1.

After the parts are secured into position shown, slots X, X are cut with a hack-saw or milling tool, thus interrupting the continuity of the ring; into these slots suitable insulation, as a sheet of mica or hard fiber, may be inserted, or the parts may be separated merely by the air space. The arrows show the course of the current in the different views. As thus described, two castings are necessary to make the one turn; but in the modified form of coil shown in Figs. 3 and 4, the castings on the right and left respectively of the part G connecting them are interchangeable. In this form lugs or tongues F, F are provided on diagonally opposite corners of the casting and upon assembling the parts of the coil as many turns as may be desired may be formed by connecting the lugs F, F by means of a conducting piece G, as fully shown in Fig. 3. As in the case of Figs. 1 and 2, after the slots Y, Y, are cut any suitable insulation may be inserted or not, as may be desired. The coils thus made, as will be seen, are adapted to carry very heavy currents and are of small cost.

The particular construction shown and described is that which we have found desirable for electric meters; but we do not mean to limit ourinvention to this alone, as it is manifest that it may be extended to other forms of field coils, where the continuity of the tube or ring is interrupted by a spiral slot, such a form being well adapted for series coils in a dynamo electric machine.

Having thus described our invention, what we claim as new, and wish to protect by Letters Patent of the United States, is-

1. The method of constructing field-magnet coils, which consists in forming a ring provided with terminals and then breaking the continuity of the ring by a cut, substantially as described.

2. The method of constructing field-magnet coils, which consists in forming a ring provided with terminals, breaking the continuity of the ring by a cut, and then inserting insulation into the cut, substantially as described.

3. The method of constructing field-magnet coils, which consists in casting a copper ring of suitable cross section provided with a lug or tongue to be used as a terminal, and then breaking the continuity of the ring by a cut.

4. The method of constructing field-magnet coils, which consists in casting a copper ring of suitable cross section provided with a lug or tongue to be used as a terminal, breaking the continuity of the ring by a cut, and then inserting insulation into the cut.

5. As an article of manufacture, a coil for a field-magnet, composed of a ring or tube the continuity of which is interrupted by a S 0t.

6. As an article of manufacture, a coil for a field-magnet, composed of a ring the continuity of which is interrupted by a slot with insulation therein.

7. As an article of manufacture, a fieldmagnet coil, consisting of a ring of cast copper, the continuity of which is interrupted by a slot or slots, the ring being provided with lugs adapted to serve as terminals.

8. As an article of manufacture, field-[nagnet coils for an electric meter, adapted to be JOSEPH JOHNSON. CARYL I). IIASKINS.

Witnesses:

JOHN W. GIBBONEY, BENJAMIN B. HULL. 

